Yep, I agree with Torp, I'd keep everything up front with the wife. I also think sharing sexual fantasies is a good idea; it gives you an idea as to what she likes, and it also gives you the opportunity to share your desire as a sexual fantasy of your own to see how she reacts. If that goes well, get some IR videos and watch those together. The fact that she's already playing some sexy games with you is a good sign she's willing to experiment a bit. The "dogging" thing ... I just have problems with strangers in a park coming up and whipping out their dicks for her to suck & fuck. Torp pointed those concerns out; this is your wife, her safety should be your #1 concern. If you've never shared your wife with another man, I'd suggest doing it in a more controlled environment ... motel, club, home, etc. Play "safe" ! Sharing your woman with other men can be a life changing event.
Like a good wine, some things just take time. Mac